1. Field of the Invention
The invention concerns a device for storing liquids, which consists of a plastic container produced by a blowing process, has a single-layer or multilayer wall, and is provided with at least one filling and emptying hole.
2. Description of the Related Art
To hold liquids, especially rainwater and wastewater, devices are used, which consist of a plastic container, which is often installed underground or buried in the ground. Plastic containers of this type are produced mainly by rotational molding with the use of glass fibers or by blow molding. Mainly high-molecular-weight high-density polyethylene, which not only is inexpensive, but also can be easily processed and is highly durable, is used for containers produced by blow molding. However, blow-molded plastic containers are limited in their size. This is related to the fact that very large containers require large and thus expensive blow molds. Moreover, high transportation costs are associated with very large containers.
In order to obtain a large storage volume with containers of this type, it is known, in the case of above-ground installation, that several smaller blow-molded containers can be arranged side by side and connected with one another by a filling line, an emptying line, and a venting line. Despite this interconnection of the individual containers, there is always the danger that the individual containers cannot be uniformly filled and uniformly or completely emptied. Containers stored underground must be designed in such a way that they are able to withstand the loads to which they are subjected by the weight of the soil and lifting forces due to groundwater.